In general, neuromodulation refers to the modulation of the nervous system. Neuromodulation may include medical procedures that alter or modulate the function of the nervous system in order to, for example, treat a disease or provide pain relief. The medical procedures may include providing electrical stimulation by, for example, an implantable pulse generator (IPG) or a transcutaneous electrical nerve stimulation (TENS) device, lesioning of specific regions of the nervous system, or the infusion of substances (e.g. pharmaceutical drugs) into the cerebrospinal fluid or brain tissue by, for example, a drug infusion pump.
Deep brain stimulation (DBS) is a surgical treatment involving the implantation of a medical device, similar to a pacemaker, which sends electrical impulses to specific parts of the brain. DBS directly changes brain activity in a controlled manner and its effects are reversible (unlike those of lesioning techniques).
Generally, the DBS system consists of three components: the IPG, at least one electrode (or “lead”), and at least one extension. The IPG is a battery-powered neurostimulator which sends electrical pulses to the brain to modulate neural activity at the target site. The electrode may be a coiled wire insulated in polyurethane terminating with multiple platinum iridium contacts and is placed in or on the target area of the brain. Electrodes are placed in the brain according to the type of symptoms to be addressed.
In some cases, all three components of the DBS system are surgically implanted inside the body. Typically, the electrode is connected to the IPG by the extension, an insulated wire that runs from the head and down the side of the neck behind the ear to the IPG, which may be placed subcutaneously below the clavicle or in some cases, the abdomen. The IPG may be calibrated to optimize symptom suppression and control side effects.
Implantable drug infusion systems generally include drug infusion pumps and catheters. The pump is generally implanted in the patient's abdomen and the catheter, which is connected to the pump, is implanted in the space surrounding the spinal cord. For example, an intrathecal pump includes a metal pump which stores and delivers the drug, and a catheter which delivers the drug from the pump to the intrathecal space in the spine. Generally, there are two types of pumps: a programmable pump which delivers the drug at a rate determined by a programmable computer program (or according to instructions provided to the computer by a clinician) and a constant rate pump which delivers the drug at a constant rate. The catheter may also be inserted into the brain to deliver the drug into the cerebral spinal fluid or the brain tissue.
IPGs and implantable drug infusion systems are designed to have long lifetimes or to be easily rechargeable. However, the connections between the pump device and the infusion site or the IPG and the site of modulation are under the patient's skin. This may cause the patient discomfort and the device (IPG or pump) may be more susceptible to the failure of its hardware, or to erosion of the patient's skin covering its parts or connections, thereby increasing the risk of patient infection.
Therefore, a need exists for devices and systems for the implantation of neuromodulation devices that reduce patient discomfort and risk of infection and reduce the risks of device hardware failure or skin erosion.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded as subject matter by which the scope of the invention is to be bound.